Legislation could be introduced before the end of this Parliament to tackle the exploitation of workers on zero-hours contracts, Business Secretary Vince Cable has announced.
Mr Cable floated proposals for new protections as part of a package of measures designed to make the workplace and wages "fairer for everyone", which also featured moves to deal with rogue company directors and new research on the possibility of more generous increases in the minimum wage.
Aides said that the moves - which have approval across the coalition Government - were a mark of the extent to which Liberal Democrat ministers have shifted the agenda on employment rights since Conservatives last year failed to push through the recommendations of the Beecroft Report to let bosses "fire at will".
The Office for National Statistics has estimated that around 250,000 workers are on zero hours contracts - under which they have no guarantee of how much work they will be given each week - but the Chartered Institute of Personnel and Development put the figure closer to one million, while a recent union survey suggested the arrangements could affect as many as 5.5 million.
Mr Cable ordered an internal review by his Department for Business and Skills earlier this year, which revealed that the contracts were "much more widely used than we had previously thought".
In a keynote speech to the Liberal Democrat conference in Glasgow, he will announce a consultation to explore how to tackle abuses - particularly relating to the issue of "exclusivity", where employers do not offer guaranteed hours but insist that workers do not work for anyone else.
The consultation is expected to conclude in the new year and aides said that it could result in legislation in next May's Queen's Speech, if Government time is available. There will be no promise to ban zero hours contracts or exclusivity agreements, as Mr Cable believes that they are suited to some occupations.
But he is likely to press ahead with plans to create a legal definition of a zero-hours contract; limit exclusivity clauses; ensure bosses make clear how much a worker can expect to earn each month; and end the "climate of fear" under which some workers dare not turn down shifts out of anxiety that they will be frozen out from future employment.
Mr Cable will say: "It is clear that there are abuses in the system, especially around the issue of exclusivity which some employers are demanding from workers on these contracts. I am determined to make sure people are paid and treated fairly, while helping to keep people employed in these delicate economic times."
He will also announce he intends to legislate to make it easier to prosecute fraudulent or reckless directors, in the wake of scandals affecting the banking sector, nursing homes and the Christmas savings firm Farepak.